All water systems in Ohio
4,165 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Athens PWS Athens County |
32,725 | 1 | 1 | |
|
Aqua Ohio Ashtabula Ashtabula County |
32,342 | 1 | 1 | |
|
Brown County Rural Water Brown County |
32,090 | 0 | 0 | |
|
Kings Island PWS Warren County |
31,753 | 2 | 0 | |
|
Painesville City PWS Lake County |
31,728 | 1 | 1 | |
|
Bowling Green City Wood County |
31,578 | 1 | 0 | |
|
Barberton City Summit County |
31,298 | 0 | 0 | |
|
Nawa Miami County |
29,974 | 1 | 1 | |
|
Kent City PWS Portage County |
29,662 | 1 | 0 | |
|
Zanesville PWS Muskingum County |
29,381 | 0 | 0 | |
|
Xenia City PWS Greene County |
29,000 | 0 | 0 | |
|
Highland County Water Company, Inc. Highland County |
28,421 | 0 | 0 | |
|
Perrysburg City PWS Wood County |
27,000 | 1 | 0 | |
|
Belmont Co. Sanitary District 3 PWS Belmont County |
26,822 | 3 | 1 | |
|
Wooster City PWS Wayne County |
26,618 | 1 | 1 | |
|
Troy City PWS Miami County |
26,305 | 0 | 0 | |
|
Medina City PWS Medina County |
25,956 | 0 | 0 | |
|
Sandusky City Erie County |
25,793 | 1 | 0 | |
|
Marysville City PWS Union County |
25,571 | 2 | 1 | |
|
North Canton City PWS Stark County |
24,747 | 0 | 0 | |
|
Wadsworth City PWS Medina County |
24,356 | 1 | 1 | |
|
Tate-Monroe Water Association PWS Clermont County |
24,092 | 1 | 1 | |
|
Avon City PWS Lorain County |
24,060 | 1 | 1 | |
|
Oxford City PWS Butler County |
24,000 | 0 | 0 | |
|
Avon Lake City PWS Lorain County |
23,659 | 1 | 0 | |
|
Alliance City PWS Stark County |
22,232 | 0 | 0 | |
|
Niles City PWS Trumbull County |
21,961 | 1 | 1 | |
|
Adams County Regional Water District Adams County |
21,810 | 0 | 0 | |
|
Chillicothe City PWS Ross County |
21,725 | 2 | 1 | |
|
Sylvania City Lucas County |
21,618 | 2 | 1 | |
|
Muskingum County Water SE Muskingum County |
21,540 | 1 | 0 | |
|
Gallia CO Rural Water Association Gallia County |
20,995 | 1 | 1 | |
|
Lebanon City Warren County |
20,700 | 0 | 0 | |
|
Ashland City Ashland County |
20,648 | 2 | 1 | |
|
Sidney City PWS Shelby County |
20,614 | 2 | 1 | |
|
Ottawa County Regional Water District Ottawa County |
20,428 | 0 | 0 | |
|
Piqua City PWS Miami County |
20,354 | 2 | 2 | |
|
Aqua Ohio Tiffin Seneca County |
20,279 | 1 | 1 | |
|
Oregon City Lucas County |
19,950 | 2 | 0 | |
|
Norwood City PWS Hamilton County |
19,870 | 1 | 1 | |
|
Miamisburg City PWS Montgomery County |
19,790 | 1 | 1 | |
|
Northwestern W and SD Toledo Svc Area Wood County |
19,332 | 2 | 1 | |
|
Le-Ax Regional Water District PWS Athens County |
19,311 | 1 | 1 | |
|
Springboro PWS Warren County |
19,263 | 1 | 0 | |
|
Pickerington City PWS Fairfield County |
19,141 | 1 | 1 | |
|
Fairfield County Utilities PWS Fairfield County |
19,113 | 0 | 0 | |
|
Berea City PWS Cuyahoga County |
18,789 | 1 | 1 | |
|
Marietta City PWS Washington County |
18,707 | 2 | 1 | |
|
Tallmadge City PWS Summit County |
18,394 | 1 | 1 | |
|
Fremont City Sandusky County |
18,319 | 2 | 1 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Ohio records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.